肌内脂肪与背最长肌肉质、脂肪酸组成的关系

研究肌内脂肪（IMF）含量与肉质以及脂肪酸含量和组成比例之间的关系。以北京黑猪背最长肌（n=20）为实验材料,测定肌内脂肪含量、肉质以及脂肪酸含量和组成。结果显示,肌内脂肪含量与滴水损失呈显著正相关（p<0.05）,与蒸煮损失、剪切力、肉色的相关性不显著（p>0.05）。随着肌内脂肪含量升高,除长链多不饱和脂肪酸(C_20:3n6、C_20:4n6)以外的大多数脂肪酸含量增加,相对比例也上升;多不饱和脂肪酸的含量增加,但是相对比例下降;长链多不饱和脂肪酸的含量和相对比例都降低。随着肌内脂肪含量的升高,饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）的含量升高,回归方程斜率分别为197.3和248.31,多不饱和脂肪酸（PUFA）增加的幅度不大,回归方程的斜率为11.43。结果提示:肌内脂肪含量较低时（本实验平均值2.86%）,对肉质的影响不显著。随着肌内脂肪含量升高,总脂肪酸含量（TFA）增加,主要归因于SFA和MUFA含量的增加。PUFA的含量相对稳定,受肌内脂肪含量变化的影响较小。      

坚果中脂肪含量及脂肪酸组成分析

目的分析16种市售坚果中脂肪含量及脂肪酸组成,比较不同品种坚果间脂肪含量、饱和脂肪酸和不饱和脂肪酸组成的差异。方法采用气相色谱分析法测定坚果中37种脂肪酸的含量,用最小显著性差异法(least-significant difference,LSD)法进行多重比较。结果坚果的平均脂肪含量为(55.6±0.86)g/100 g,变化范围为40.2~71.3 g/100 g,碧根果脂肪含量显著高于其他品种坚果脂肪含量(P0.05);坚果中的不饱和脂肪酸含量为72.77~95.47 g/100 g脂肪,平均值为(86.68±0.12)g/100 g脂肪,显著高于饱和脂肪酸4.53~22.19 g/100 g脂肪,平均值为(11.31±0.16)g/100 g脂肪(P0.05),东北榛子中单不饱和脂肪酸总含量最高,为84.34 g/100 g脂肪,而纸皮核桃中的多不饱和脂肪酸总含量最高,为74.17 g/100 g;坚果中不含短链脂肪酸和中链脂肪酸。结论坚果中不饱和脂肪酸含量较多,富含ω-6和ω-3脂肪酸,营养价值较高。     

Association between polymorphisms of the heart fatty acid binding protein gene and intramuscular fat content,fatty acid composition,and meat quality in Berkshire breed

The objective of this study was to examine the relationship between polymorphisms of the heart fatty acid binding protein (H-FABP) gene and variation in intramuscular fat (IMF) content, fatty acid composition, and meat quality in Berkshire breed. We detected an association between IMF content and H-FABP HinfI restriction fragment length polymorphism (RFLP) genotype. The HH genotype showed the greatest IMF content among the genotype classes (P < 0.05). Regarding meat quality traits, only drip loss was significantly different among the H-FABP HinfI RFLP genotype classes (P < 0.01). In the case of fatty acid composition, the degree of saturation of fatty acids was greater in hh-genotype pigs than in HH and Hh genotypes. The H-FABP MspI RFLP genotype affected unsaturated fatty acid content, and the ratio of polyunsaturated fatty acid to saturated fatty acid (P < 0.05), whereas the H-FABP HaeIII RFLP genotype had no effect on fatty acid characteristics.     

不同部位猪脂的总脂肪酸组成及Sn-2位脂肪酸成分分析

选择11例猪的4个部位(猪尾巴、猪脖、奶腩和猪板),用乙酸甲酯萃取脂肪,采用DIKMA CP-SIL88FS(60 m×0.25 mm id×0.20μm)毛细管柱气相色谱对各部位猪脂总脂肪酸及Sn-2位脂肪酸组成进行了测定,并采用SPSS 13.0软件对数据进行统计分析。结果表明:猪尾巴油、猪脖油和奶腩油的总脂肪酸及Sn-2位脂肪酸组成和分布与猪板油相比均存在显著性差异,且不饱和脂肪酸和单不饱和脂肪酸含量均高于猪板油。     

Efficacy of a novel whey protein gel complex to increase the unsaturated fatty acid composition of bovine milk fat

A novel whey protein emulsion gel (WPEG) complex was developed to protect dietary unsaturated fatty acids from rumen biohydrogenation with the goal of modifying the fatty acid composition of milk fat. Three experiments were conducted with WPEG complexes made from either whey protein concentrate containing 80% crude protein, whey protein isolate, or whey protein concentrate high-gel capacity. Each experiment lasted 3 wk. All cows received a basal total mixed ration (TMR). During wk 1 and 3, all cows received only the TMR. During wk 2, 3 control cows received 330 g/d of soybean oil added to the TMR, and the other 3 cows received 330 g/d of soybean oil in one of the WPEG complexes. During wk 2, C18:2 increased from 3.29 to 5.88 g/100 g of fat in Experiment 1, 2.91 to 7.42 g/100 g of fat in Experiment 2, and 3.57 to 6.56 g/100 g of fat in Experiment 3 for WPEG cows. Fatty acid C18:3 increased from 0.51 to 0.84, 0.52 to 1.15, and 0.51 to 0.97 g/100 g of fat for Experiments 1, 2, and 3, respectively, for WPEG cows. Higher proportions of C18:1 trans-9 in milk fat of control cows compared with WPEG cows were seen in all experiments. The proportion of C18:1 trans-11 was also higher in control cows in Experiments 1 and 2, but not in Experiment 3. The WPEG complexes successfully protected unsaturated fatty acids from rumen biohydrogenation and resulted in an increase in the unsaturated fatty acid composition of milk fat produced by Holstein cows without increasing the trans 18-carbon monoenes.     

不同畜禽肌肉脂肪酸组成的对比分析

采用GC-MS测定猪、牛、鸡、兔后腿肌脂肪酸组成的相对百分含量和实际当量,测定结果表明四者的主要脂肪酸组成有17种,其中棕榈酸（16∶0）、硬脂酸（18∶0）、油酸（18∶1n-9）、亚油酸（18∶2n-6）和花生四烯酸（20∶4n-3）的总含量占肌肉总脂肪酸含量分别为84.35%、79.71%、81.78%、81.19%。n-6/n-3比率猪肉最高,鸡肉、兔肉次之,牛肉最低。就综合营养价值而言,兔肉最高,牛肉、鸡肉次之,猪肉最低。      

地理经纬度对油茶籽中脂肪及脂肪酸组成的影响

对我国油茶主产区34个点的油茶籽的粗脂肪和脂肪酸组成与地理经纬度的关系进行了分析.相关分析结果表明,油茶籽的粗脂肪含量与地理经度和纬度均有显著的负相关关系,油茶籽油的脂肪酸组成中硬脂酸含量与地理纬度有显著的负相关关系,而油酸与粗脂肪含量有极显著的正相关关系.油茶籽油中油酸的变化趋势呈散点分布,并确定出15个高油酸含量的油茶分布区.通过对硬脂酸进行聚类分析将油茶主要分布区分为4大主要区域.     

The effects of sources of supplemental fat on performance,egg quality,and fatty acid composition of egg yolk in laying hens

BACKGROUND: The objective of this study was to determine the effects of sources of supplemental fat on laying performance, egg quality, and fatty acid composition of egg yolk. RESULTS: Two hundreds Isa Brown layers were assigned randomly to be fed ad libitum a standard commercial layer feed (BD), basal diet plus 2% tallow (T), basal diet plus a mixture of 1% tallow and 1% flaxseed oil (MTFO), basal diet plus 2% sunflower oil (SO), or basal diet plus 2% flaxseed oil (FO), which were offered for 8 weeks. Each diet was given to five groups, each containing 10 hens. The feed efficiency and egg production were 2.78 and 53.51% for BD; 2.30 and 63.47% for T; 2.45 and 60.14% for MTFO; 2.29 and 64.30% for SO, and 2.62 and 61.18% for FO groups, respectively. Dietary fat supplementation affected the laying performance but had no significant effects on egg quality parameters. The fatty acid composition of egg yolk lipids were significantly affected by dietary fatty acid composition. The supplemental tallow increased palmitic fatty acid. The proportions of linoleic and arachidonic fatty acids in egg yolks for layers fed the SO diet were higher than in the BD group and those on diets containing other fats. Concentrations of oleic and omega‐3 fatty acids were the highest in layers fed the FO diet during the laying period. CONCLUSION: The results indicated that dietary animal and plant fats changed the fatty acid composition of egg yolk. Copyright © 2008 Society of Chemical Industry     

Impact of milking frequencies on the level of free fatty acids in milk, fat globule size, and fatty acid composition

The aim of the present study was to study the effect of milking cows 4 times daily on free fatty acids (FFA) in the milk compared with milking twice daily. An experiment was performed during 2 wk in which half udders in 11 cows were milked 2 or 4 times daily. Milk yield was measured, and milk was analyzed for fat content, FFA, fatty acid composition, fat globule size, and activity of γ-glutamyl transpeptidase. Concentration of FFA was greater (1.49 mEq/100 g of fat) in milk from half udders milked 4 times daily than in milk from the half udders milked twice daily (1.14 mEq/100 g of fat). Further, it was noted that milk from the half udder milked 4 times daily contained milk fat globules with larger average diameters. Increased milking frequency increased milk yield by 9% compared with the udder half milked twice daily, but fat content and fat yield were not affected. The results are of importance for further understanding the mechanisms behind the increased content of FFA that is frequently observed in automatic milking systems.     

Impact of fatty acid composition on the accuracy of mid-infrared fat analysis of farm milks

Our objective was to determine whether data from a previous study using model milk emulsions to characterize the influence of variation in fatty acid chain length and unsaturation on mid-infrared (MIR) fat predictions could be used to identify a strategy to improve the accuracy of MIR fat predictions on a population of farm milks with a wide variation in fatty acid chain length and unsaturation. The mean fatty acid chain length for 45 farm milks was 14.417 carbons, and the mean unsaturation was 0.337 double bonds per fatty acid. The range of fatty acid chain lengths across the 45 farm milks was 1.23 carbons, and the range in unsaturation was 0.167 double bonds per fatty acid. Fat B (absorbance by the carbon-hydrogen stretch) MIR predictions increased and fat A MIR (absorbance by the ester carbonyl stretch) predictions decreased relative to reference chemistry with increasing fatty acid chain length. When the fat B MIR fat predictions were corrected for sample-to-sample variation in unsaturation, the positive correlation between fat B and fatty acid chain length increased from a coefficient of determination of 0.42 to 0.89. A 45:55 ratio of fat B corrected for unsaturation and fat A gave a smaller standard deviation of the difference between MIR prediction and reference chemistry than any ratio of the fat B (without correction for unsaturation) and fat A or either fat B or fat A alone. This demonstrates the technical feasibility of this approach to improve MIR testing accuracy for fat, if a simple procedure could be developed to determine the unsaturation of fat in milk rapidly and to correct the fat B reading for the effect of unsaturation before being combined with fat A.     

Prepartum nutrition alters fatty acid composition in plasma, adipose tissue, and liver lipids of periparturient dairy cows

The fatty acyl profile of phospholipids (PL) determines the fluidity of cell membranes and affects cell function. The degree to which long-chain fatty acid (LCFA) composition of PL and triacylglycerols (TG) in liver and total lipids in adipose tissue can be altered by prepartum nutrition in peripartal dairy cows is unclear. Multiparous Holsteins (n = 25) were assigned to 1 of 4 prepartal diets: 1) CA, the control diet fed to meet 120% of energy requirements; 2) CR, a control diet fed to meet 80% of requirements; 3) S, a diet supplemented with mostly saturated free fatty acids (47% 16:0, 36% 18:0, 14% cis-18:1) and fed to meet 120% of requirements; or 4) U, a diet similar to S except that cows were abomasally infused with soybean oil so that the diet plus infused fat would meet 120% of requirements. Diets were fed for 40 d prepartum; all cows received a lactation diet postpartum. Groups CR and U had lower prepartum intakes of dry matter and net energy, but glucose concentrations in plasma were similar among treatments. Cows fed S, U, or CR had greater nonesterified fatty acids in plasma prepartum, but cows fed U had decreased β-hydroxybutyrate postpartum. Postpartal concentrations of total lipids and glycogen in liver tissue were similar among treatments. Cows in group U had a greater percentage of 18:2 but less 16:0, 18:0, and 20:4 in plasma total lipids than cows fed S. Treatment U increased 18:2 and 18:3 and decreased 18:1 in subcutaneous adipose tissue at 1 d postpartum. Across diets, percentages of 16:0 and trans-18:1 were increased, and 18:0, 20:3, and 20:5 were decreased, in hepatic PL at d 1 postpartum. Significant treatment × time interactions indicated that treatment U increased 18:2 in hepatic PL at the expense of 18:1, 20:3, 20:4, 22:6, and 24:0 on d 1 postpartum, but changes were normalized by d 65 postpartum. The unsaturation index of hepatic PL was lower at d 1 than at d −45 or 65, which implies that hepatic membrane fluidity decreased around parturition. The unsaturation index at d 1 was greater for cows fed S than those fed CA or U. Percentages of 16:0, 18:1, and 22:0 were increased, and 18:0, 20:3, 20:4, 20:5, 24:0, and 26:0 were decreased, in hepatic TG at d 1. Prepartal feed restriction modestly affected tissue LCFA profiles. The LCFA profile of adipose tissue, liver PL, and liver TG can be altered by dietary LCFA supply prepartum; changes in liver are normalized by 65 d postpartum.     

Effect of feeding oilseed supplements to dairy cows on ruminal and milk fatty acid composition

The objective of this study was to compare the effects of oilseed‐based supplements, rapeseed and linseed, against a barley‐based control, on the fatty acid composition, and subsequent solid fat ratio, of the milk fat from dairy cows. In addition, as a means of understanding the digestive processes which influence the milk fat composition, ruminal extracts were collected from the cows and analysed for fatty acid composition. Four lactating dairy cows each fitted with a rumen fistula were provided with silage and one of four concentrate diets. The main constituent of the concentrate supplements was either rapeseed (ground or unground), linseed (unground) or a barley control. The diets were offered in accordance with a 4 × 4 Latin square arrangement. The oilseed‐supplemented concentrates provided the cows with 620–640 g fatty acids day^?1. Experimental treatments were provided to the cows for 2 weeks, after which ruminal extracts were collected over a 24 h period and a milk sample was taken. All extracts were analysed for fatty acid composition. The diets fed influenced the long‐chain fatty acid composition of the ruminal extracts and milk fat. The proportion of C18:1n‐9 in the ruminal extracts increased from 202–224 to 282–321 g kg^?1 of the total fatty acids when the cows were provided with the rapeseed‐based diets. The linseed‐based diet increased the C18:1n‐9 proportion of the ruminal extracts from 164 to 218 g kg^?1 of the total fatty acids. Both rapeseed‐based diets also resulted in a higher proportion of C18:0 in the ruminal extract, possibly owing to biohydrogenation of the dietary fatty acids. This proportion of C18:0 in the ruminal extract was lowest immediately after feeding, increasing to a maximum 4–6 h later. Both rapeseed‐based concentrates increased the proportion of C18:1n‐9 in the milk fat to approximately 300 g kg^?1 of the total fatty acids as compared with 214 g kg^?1 for the control. The proportion of C18:1n‐9 in the milk fat from the cows offered the linseed‐based concentrate was 246 g kg^?1 of the total fatty acids. There were also significant decreases in the proportions of C16:0 in the milk fat from the cows offered all oilseed‐based concentrates. There was no difference between the fatty acid compositions of the milk fats from the cows fed the ground or unground rapeseed‐based supplements. The oilseed‐based supplements also resulted in significant decreases in the solid fat content of the milk fat at temperatures ranging from 0 to 35 °C, which would be indicative of a softer, more spreadable butter. © 2002 Society of Chemical Industry     

两种杂交商品猪冷却肉常规养分含量、蛋白质溶解性及脂肪酸组成的比较

通过比较含地方猪血缘的杂交商品猪(杜浙猪)与外三元杂交商品猪(杜大长)背最长肌和腰大肌冷却肉的常规养分、蛋白质溶解度及脂肪酸组成,深入评价含地方猪血缘的杂交商品猪在优质猪肉生产中的优势。结果表明,杜浙猪背最长肌冷却肉的粗蛋白和粗脂肪含量显著高于杜大长猪(p<0.05),粗灰分含量显著低于杜大长猪(p<0.05);杜浙猪背最长肌和腰大肌冷却肉的肌浆蛋白溶解度均显著高于杜大长猪(p<0.05),纤维蛋白溶解度显著低于杜大长猪(p<0.05);杜浙猪背最长肌和腰大肌冷却肉的饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸含量均显著高于杜大长猪(p<0.05)。综合上述指标,杜浙猪冷却肉的营养价值和蛋白质功能性优于杜大长猪,将为充分利用地方猪种资源进行优质猪肉生产提供依据。      

伊拉兔肉肌内脂肪酸组成及温度对其脂肪氧化的研究

研究了伊拉肉兔后腿肉的肌内脂肪含量,并分析测定了其脂肪酸组成,同时研究了兔腿肉在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下的脂肪氧化稳定性。结果表明,兔腿肉肌内脂肪主要含有19种脂肪酸,其中棕榈酸(16∶0)、硬脂酸(18∶0)、油酸(18∶1)、亚油酸(18∶2)的总含量占脂类总脂肪酸含量的71.06%左右。伊拉兔肉肌内脂肪中主要是不饱和脂肪酸,尤以多不饱和脂肪酸居多。在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下,兔腿肉POV、TBA值的差异极显著(p<0.01)。常温条件下,第5d兔肉出现异味并逐渐变成臭味,而低温条件下,第7d才开始出现轻微异味,低温冷藏对保证肉品质量有重要意义。      

采收期对“鄂选2号”山桐子果实成分及脂肪酸组成变化影响

为探寻木本油料山桐子果实及种子中油脂的积累动态规律,对不同采收期的预选品种“鄂选2号”的山桐子果实的整果、果肉和种子中的基本化学成分含量进行比较,并运用气相色谱-质谱联用对不同部位的油脂中的脂肪酸组成进行测定。结果表明,“鄂选2号”山桐子油料最佳采收期为盛花期后128 d左右,此时山桐子全果平均含油率为40.25%,果肉中的平均含油率为44.60%,种子中的平均含油率为30.55%。果实各部位的主要脂肪酸组成主要为肉豆蔻酸(C14∶0)、棕榈酸(C16∶0)、棕榈油酸(C16∶1)、珍珠酸(C17:0)、硬脂酸(C18∶0)、油酸(C18∶1)、亚油酸(C18∶2)、γ亚麻酸(C18∶3n6)、花生酸(C20∶0)、山嵛酸(C22∶0),其中种子油脂中亚油酸质量分数高于整果和果实,高达61.43%。     

Effects of conjugated linoleic acid supplementation and feeding level on dairy performance,milk fatty acid composition,and body fat changes in mid-lactation goats

The objective of this trial was to study the interaction between the supplementation of lipid-encapsulated conjugated linoleic acid (CLA; 4.5 g of cis-9,trans-11 C18:2 and 4.5 g of trans-10,cis-12 C18:2) and feeding level to test if milk performance or milk fatty acid (FA) profile are affected by the interaction between CLA and feeding level. Twenty-four dairy goats were used in an 8-wk trial with a 3-wk adaptation to the experimental ration that contained corn silage, beet pulp, barley, and a commercial concentrate. During the third week, goats were assigned into blocks of 2 goats according to their dry matter intake (DMI), raw milk yield, and fat yield. Each block was randomly allocated to control (45 g of Ca salt of palm oil/d) or CLA treatment. Within each block, one goat was fed to cover 100% (FL100) of the calculated energy requirements and the other was fed 85% of the DMI of the first goat (FL85). Individual milk production and composition were recorded weekly, and milk FA composition was analyzed in wk 3, 5, and 7. Conjugated linoleic acid supplementation reduced milk fat content and fat yield by 17 and 19%, respectively, independent of the feeding level. It reduced both the secretion of milk FA synthesized de novo, and those taken up from the blood. No interaction between CLA and feeding level was observed on milk secretion of any group of FA. The CLA supplementation had no effect on DMI, milk yield, protein, and lactose yields but it improved calculated net energy for lactation balance. Goats fed the FL100 × CLA diet tended to have the highest DMI and protein yield. The interaction between CLA and feeding level was not significant for any other variables. Compared with the goats fed FL100, those fed FL85 had lower DMI, lower net energy for lactation balance, and lower digestible protein in the intestine balance. The body weight; milk yield; milk fat, protein, and lactose yields; and fat, protein, lactose, and urea contents in milk were not affected by feeding level. In conclusion, reduction in energy spared via fat yield reduction after CLA supplementation was not partitioned toward milk lactose or protein in goats at a low feeding level, possibly because of a simultaneous shortage of energy and amino acids. In goats on the high feeding level, energy spared tended to be partitioned toward milk protein yield, and at the same time to the prevention of excessive lipid mobilization.     

Principal component and multivariate analysis of milk long-chain fatty acid composition during diet-induced milk fat depression

The objective of this study was to assess the relationship between individual milk fatty acids (FA) and diet-induced milk fat depression (MFD) using principal component analysis (PCA) and multivariate analysis (MA). Cow treatment observations (n = 63) from 3 published feeding experiments with lactating dairy cows were used in the analyses. In the PCA, principal component loading plots 1 (PC1) and 2 (PC2) described 55.9% of the total variation in milk FA and fat concentrations. Saturated FA (14:0, 16:0, and 17:0) and milk fat percentage showed negative loading for PC1. Trans-18:1 isomers (trans-6+7+8 to trans-15), trans-7, cis-9 conjugated linoleic acid (CLA), and trans-10, cis-12 CLA showed positive (opposite) loading, suggesting a negative relationship between these isomers and milk fat percentage. Cis-11, trans-13 CLA and cis-9, trans-11 CLA were associated with the PC2 axes (neutral), indicating that they were not associated with MFD. Multivariate analysis with milk fat percentage as the dependent variable and individual PC1 positive loading variables showed a breakpoint relationship for trans-6+7+8-, trans-9-, trans-10-, and trans-13+14-18:1 and a linear relationship for trans-11-, trans-12-, trans-15-18:1, trans-10, cis-12 CLA, and trans-7, cis-9 CLA. Subsequent MA was conducted on 41 treatment means from 12 independent experiments from the literature, in which concentrations of trans-6+7+8-, trans-9-, trans-10-, and trans-11-18:1, and cis-9 trans;-11, and trans-10, cis-12 CLA were reported. Significant negative effects of trans-9-18:1, trans-10-18:1, and trans-10, cis-12 CLA on milk fat percentage were observed. In this study, the PCA and MA showed that among trans-18:1 isomers, trans-10-18:1 was the most negatively correlated to milk fat percentage. However, the threshold concentration related to maximum MFD indicated that the relative potency was greatest for trans-6+7+8- and lowest for trans-10-18:1. These results suggested that trans-6+7+8-18:1 might be more important than trans-10-18:1 in MFD. Principal component analysis also showed that trans-10, cis-12 and trans-7, cis-9 CLA were the isomers most negatively correlated to milk fat percentage, implying a possible role of trans-7, cis-9 CLA in MFD. Additional experiments are needed to establish whether trans-7-18:1 is involved in MFD or that its effects are mediated via the endogenously synthesized trans-7, cis-9 CLA.     

Effect of dietary flax seed and oil on milk yield,gross composition,and fatty acid profile in dairy cows: A meta-analysis and meta-regression

Several experiments were conducted over the past few years to evaluate the feeding value of flax seed and oil in dairy cow diets. The current meta-analysis and meta-regression was undertaken to assess the overall effect of different forms of flax, as a source of trienoic (cis-9,cis-12,cis-15 18:3) fatty acids (FA), on lactation performance and on transfer efficiency of its constituent n-3 FA from diet to milk fat. Comparisons were first conducted with nonsupplemented controls or with diets containing either saturated (mainly 16:0 or 18:0 or both), monoenoic (mainly cis-9 18:1), or dienoic (mainly cis-9,cis-12 18:2) FA. Results indicate that supplementing flax seed and oil decreased dry matter intake, as well as actual and energy-corrected milk yield without affecting the efficiency of utilization of dietary dry matter or energy as compared with nonsupplemented iso-energetic controls. When compared with the other 3 types of dietary fat evaluated, flax rich in trienoic FA supported a yield of energy-corrected milk similar to supplements rich in saturated, monoenoic, or dienoic FA. Greater milk fat concentration and feed efficiency were observed with saturated supplements. However, milk fat concentration and yield were lower with dienoic FA than with flax supplements. Further analyses were conducted to compare the effect of different forms of flax oil, seed, or fractions of seed. Among the 6 categories evaluated, mechanically processed whole seed (rolled or ground) allowed the greatest yield of energy-corrected milk and the best feed efficiency when compared with free oil, intact or extruded whole seed, protected flax, and flax hulls. Feeding protected flax and flax hulls allowed the greatest milk fat concentration of cis-9,cis-12,cis-15 18:3. Moreover, the greatest transfer efficiencies of this fatty acid from diet to milk were recorded with the same 2 treatments, plus the mechanically processed whole seed. These results make this last category the most suitable treatment, among the 6 flax forms evaluated, to combine optimum lactation performance and protection of flax constituent cis-9,cis-12,cis-15 18:3.     

超声波对油脂脂肪酸组成影响研究

该文介绍超声波作用原理及在油脂工业上应用,综述超声波对油脂脂肪酸影响和研究前景。